Interest-calculator.



J. M. MAGLEAN. INTEREST CALCULATOR. APPLIGATION rum) NOV. 12, 1913.

Am 1 9 1 00 1 L l. T E E H S i S T u E H s 5 WITNESSES:

A on! J. M. MACLEAN.

INTEREST CALCULATOR. APPLICATION FILED NOV.12,1913.

1 ,1 1 3,801. Patented 001;. 13, 1914.

5 SHEETS'SHEET 2 VITN ESE ES: IYVF ZTOR J. M. MAGLEAN.

INTEREST CALCULATOR. APPLICATION FILED NOV.12,1913.

Patented Oct. 13, 1914.

, WITNESSES: INVENTOR Ww 1111mm BY Y a I J. M. MAOLEAN- INTEREST CALCULATOR. APP LIOATION TILED HOV.12,1913.

1,11 3,801 Patented Oct. 13, 1914.

5 SHEETS SHEET 4.

IIIHIHHI WITNESSES:

INVESTOR J. M. MACLEAN.

INTEREST CALCULATOR.

APPLICATION FILED NOV. 12, 1913.

1, 1 1 3,801 Patented Oct. 13, 1914.

5 SHEETS 'SHEET 5,

WI TN ESS ES:

TTORN I) UNITED STATES PATENT OFFICE.

JOHN M. MACLEAN, OF LA PANZA, CALIFORNIA, ASSIGNOB. OF ONE-THIRD TO FRANK K. LIPPITT AND ONE-THIRD TO THOMAS MACLAY, BOTH OF PETA.-

LUMA, CALIFORNIA.

INTEREST-CALCULATOR.

To all whom it may concern:

Be it known that I, JOHN M.- MACLEAN, a citizen of the United States, residing at La Panza, in the county of San Luis Obispo and State of California, have invented new and useful'Improvements in Interest-Calculators, of which the following is a specification. i

This invention relates to a calculating machine, and has as its object the production of a simple mechanism which is especially applicable in computing interest on various amounts for any period of time, at various rates of interest.

A further object is to provide a mechanism of the above character of large range, having a practically unlimited capacity by reason of interchangeability of calculating charts embodied therein.

A further object is to provide a calculating machine which is simple in construction, eflicient and reliable in operation, and is compact so as to occupy small space.

7 Further objects will appear hereinafter.

The invention primarily resides in a rotary carrier with a series of calculating charts wound on reels, with means for engaging and unwinding any one of the charts carried'thereby; and means by which the unwinding of any particular reel will enable the determination of correct interest amounts for any predetermined length of time, and means for rotating the chartcarrier.

The invention further consists of the parts and the construction and combination of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which Figure 1 is a perspective view of the invention. Fig. 2 is a front elevation of same. Fig. 3 is. an end elevation. Fig: 4 is a detail section and elevation on the line a-a of Fig. 3. Fig. 5 is a detail section on the line Zb of Fig. Fig. 6 is a detail section on the line cc of Fig. 2. Fig. 7 is a detail in elevation on the line dd of Fig. 6. Fig. 8 is a view partly in vertical section and partly in elevation of a chart-reel employed in this invention. Fig. 9 is a view in elevation of the annual chart-roll. Fig. 10 is a detail of the chart engaging device showing it in the engaged position. Fig. 11 is a similar view showing the chart engaging device in the disengaged position. Fig. 12 is a Specification of Letters Patent.

Application filed November 12, 1913.

Patented Oct. 13, 1914. Serial No. 800,517.

detail section on the line ee of Fig. Fig.

13 is a detail end elevation of a reel illustrating the manner ofmounting it in the reel carrier. Fig. 14 is a horizontal section on the line ff of Fig. 13.

In the drawings A indicates a pair of spaced standards of any suitable construction, on which a shaft 2 is rigidly mounted. Revolubly mounted on-the shaft 2 is aldruni or cylinder 3, having a series of longitudinally extending chambers 4 formed therein, which chambers open at one end of the cyl inder for the reception of the reels or rollers 6 and the cylinder having longitudinally peripheral slots through which the curtains or charts 7 wound 'on the rollers 6 may be withdrawn, as later described. The charts 7 are ruled longitudinally and transversely, and the spaces between the lines are printed, or otherwise marked with graduated intcrest amounts, or other tabulated matter. The charts 7 are adapted to be detachably secured to the reels or rollers 6 by means of hook tangs 8 on the inner ends of the charts 7, which hooks are engageable with notches or slots 9 in the rollers 6, as particularly shown in Fig. 6; the outer ends of the charts 7 being connected to transverse bars 10, which extend lengthwise of the slots 5, when the charts 7 are intheir wound position; the walls .of the slots 5 converging in' wardly to form abutments to limit the inward movement of the bars 10 in the slots 5, and to position the bars within the peripheral surface of the drum 3, as shown in Fig. 5, in order to allow the bars: 1.0 ordinarily to pass the stationary indicator bar 11, as later described.

Each reel 6 is tubularand has a spring tuated rod 12, similar to a Hart horn window shade roller. As shown in Figs. 13l l, the outer squared end of the rod 13 engages a loose circular plate 14-, which is adapted to be mounted ,i' the open end of a chamber 4 and abuts against a shoulder 15' formed by enlarging the outer end of the chamber 4. Theplate 14 is held in place in the cylinder 3 by means of a spring bar 16. the ends of which extend into diametrically oppo ite ockets 17 formed in the walls of the chainbcr 1. Fingers 18, formed on the bar l 'ZuHTQ adapted to engage perforations or depressions 19 in the plate 14 and act as pawls to prevent rotation oi the plate. By rotating the plat?! 14.- in one direction the rod 12 will be rotated thereby, placing its s ring 13 under tension, which spring will t on operate to normally main taih the charts 7 in a wound position on the wheel 6,

Revolubly mounted on the hub 3 of the drum 3, at each end of the latter, are the numbered count disks 20 and 20, having outside diameters corresponding to that of the drum 3; these disks 20-2() forming end closures for the chartchambers 4; a coverable opening 21 being formed in the disk 20 j.ad]acent to the open ends of the chambers 4 to permit the insertion and removal of the reels 6 and charts 7 thereon. A slot- 22 leads from the opening 21 to the outer edge of the disk 20 to permit the insertion and adjustment of a chart 7; it being necessary to insert and remove the reel 6 when the chart 7 is partially unrolled, as indicated in Fig. 3. The disks 20 and 20 are connected together by means of a carrier b31223, which extends longitudinally of the drugn'd, adjacent thereto. The bar 23 ties the-disks 2020 together, so they turn in unison. The drum is adapted to turn independently of both the disks and the carrier bar 23. The disks 2020 are graduated on their periphery from 1 to 365, corresfponding to the number of days in the year, or the urpose later to be described. The bar 23 as a straight edge which coincides I with the division between graduation 365 and graduation 1.

Mounted on the bar 23 and extending longitudinally thereof, is a rOCk shaft 24 having an arm 25 formed on its outer end, which arm has an inturned outer end to form a hook or finger 26, which is adapted to extend into depressions 27 formed in the periphery of the drum 3 and opening to the slots 5; the finger 26 being designed to engage the bars 10 on the charts 7 to draw and unwind them from the drum, as will be later described.

The outer end of the rock shaft 24 is formed with an arm 27 which extends inwardly adjacent to the outer face of the count disk 20, which arm is attached to a spring-28 connected to the disk 20 and op erating to normally maintain the finger 26 out of engagement with the bar 10 and clear of the periphery of the cylinder 3, as shown in Fig. 1]..

Mounted on the shaft 2, contiguous to the count disk 20, is a turnable calendar disk 29, corresponding in diameter to the disk. 20. Disk 29 is graduated on its periphery according to the number of days of each month in the year for the purpose later to be described. Adjacent to the outer face of the end disks 29-20 at opposite ends of drum 3 are radial arms 30 and 30, which terminate'beyond the periphery of the drum and disks and form a support for a longitudinally extending cylindricah casing 31, having the index plate 11 formed thereon. Plate 11 has a suitable straight edge which terminates contiguous to the drum 3 and carries notation which is read in connection with the charts and with the disks 2020- 29, as later described. The arms 30 and 30' are formed with hub portions 33 and 33 which surround the shaft 2 between a shoulder 2 on the shaft 2 and the inner faces of the standards A in such manner as to permit an adjustment of index plate 11 circum ferentially of the drum, and subsequently of their being clamped against movement by means of nuts 34' screwed on the threaded end portions of the shaft 2 extending through the standards A. The hub 33 has a second radial arm 34 formed thereon, which extends at an angle in relation to the arm 30 and terminates a short distance beyond the periphery of the end disk 20; the arms 30-34 supporting a graduated segment 35. On the inner side of segment 35 are two toothed racks 36-37; rack 36 being fixed and having V-shapeddownwardly extending teeth 36 on its underside; rack 37 being longitudinally movable on pins 38 carried by the rack 36, and extending through slots 39 in the movable rack 37.

The extended movement of the rack 37 is limited by the slots 39, which movement is approximately half the width of the space in the outer edges of the teeth 37 on the rack 36.- The purpose of these racks 36-37 will be seen shortly. The inclination of the two racks 3637 and the Weight of rack 37, are such that the rack 37 normally gravitates toward one end so as to throw its rack teeth out of register with the rack teeth of rack 3 On the rack 37 is a downwardly extending crank member 40, Fig. 10, which projects into the path of arm 27 on bar 24 and is adapted to engagethe arm 27 when bar 24 is brought forward against the index plate 11 and to rock the bar 24 rack 37 is moved from its normal position; the normal position of the rack 37 being thatobtained by gravitation and shown in Fi 11.

41 is a handle for turning drum 3 and which operates in conjunction with segment 35. It is mounted on an arm 42, which fulcrums on shaft 2 and extends upwardly parallel with the end disk 20 and passes through a longitudinal slot 43 formed in the segment 35. By the handle 41 the arm 42 may be rocked on its pivotal bearing to various positions in relation to the segment 35, to carry a spring pressed pawl 45 into engagement with the teeth in the racks 36-37. Pawl 45 is mounted thus: Formed in the arm 42, adjacent to the underside of the segment 35, is a guide slot 44, in which the pawl 45 is connected to a stem 46 extending upwardly through and slidable in the handle 41; apush button 47 being formed on the upper end of the stem 46 in opposition to a helical spring 48 wound thereon, wimin a recess 49 in the handle 41, and hearing between the recess 49 and a shoulder on'the stem 46 to normally maintain the latterin its uppermost position; the tooth on the pawl being normally projected by the spring toward the racks 36-457. 'The purpose of pawl 45 is to lock the arm 42 against movement and at the same time maintain the rack 37 in its upper-most position; the teeth on the rack 37 being normally offset in relation tothe teeth 36 on the rack 36 when the rack 37 is in its lower position, as shown in Fig. 11, so that the pawl will act as a wedge against the inclined face of a tooth on the rack 37' to move the rack 37 to its uppermost position with its teeth registering with the teeth on the rack 36, as shown. This will cause the rack 37 to he in such position that the finger 40 thereon will be in position to actuate the arm 27 in opposition to the spring 28 and thereby rock the shaft 24 and move the finger 26 into engagement with a chart bar 10.

. The turning of the drum is accomplished as follows: Mounted on the inner face of.

the arm- 42 is a toothed segment .51 which meshes with a large gear Wheel 52, revolubly mountedon the stud shaft 53, carried by the hub 33 on the arms 30 and 34. The gear wheel 52 meshes with the smaller pinion 54,- mounted on the hub 2' of the drum 3, and the gears 52-54 are so proportioncd that when the handle 41 and arm 42 are rocked the full limit allowed by slot 43 in segment 35, the pinion 54 will be caused torotate and thereby revolve the drum 3 through a full revolution of thelatter.

Each disappearing chart 7 is provided for a diilerent rate of interest which it is desired to calculate in the apparatus comprising this invention, such for instance as %--1-1 and 2%, and so on; the charts being arranged consecutively around the successive chambers 4 according to the capacity of the apparatus. .In the present instance the cylinder 3 is provided with a se ries of twenty-four chambers 4, and is illus trated as employing interest calculating charts from to 11-}%, on a numerically ascending scale of 2 one chamber 4 being left vacant for the reception of a chart of an odd per cent., not commonly calculated.

Formed on the upper face of the segment 35, adjacent to the slot 43, is a series of graduations 55 corresponding in number to the number of chambers 4 formed in the drum 3; the .graduations 55 being spaced apart a distance equal to the distance be tween the centers of the V-shaped spaces separating the teeth on the rack 36; and the graduations 55 being numbered according motions 55.

to the various rates of interest to be calculated, such as :}-1-1 }2% and so on, to

correspond with the percentage calculations indicated on the charts 7.

A pointer 0r indicator 56 is formed on the handle 41 and extends over the segment 35 and is adapted to register with the grad- The relative movements of the handle 41 and the drum 3 are such that when the indicator 56 is moved from one graduation 55 to an adjacent graduation, the drum 3 will rotate a distance corresponding to the interval between adjacent slots 5 on the periphery of the drum so as to bring a corresponding interest chart into juxtaposition and in a radial plane with the reading line of the indicator count plate 11.

Formed on the peripheral edge of the count disks 2020 (which latter always turn in unison) are series of graduations 57, spaced equal distances apart, and corre spondiug in number to the days of the year, that is 365; the spaces between the graduations 57 being numbered in consecutive order. The peripheral edge of the independent calendar disk 29 is also graduated, as indicated at 58; the graduations 58, howcvcr, hciug numbered according to the days of the several months, which latter are arranged consecutively.

Mounted on the vertical face of the disk 2.) and extending at right angles thereto are name plates 59 named consecutively from January to December. Plates or projections 59 are positioncd adjacent the peripheral edge of the disk 29, and are arranged opposite certain of the graduations 58, which indicate the first of the corresponding month. The projections 59 serve-as handholds by which the disk 29 may be-rotated independent of the count disks 20-20 and drum 3. Means are provided for locking the calendar disk 29 to the count disk20 so that both may be rotated in unison. This means is here shown as comprising a latch 30 slidably mounted on the carrier bar 23 with its outer end extending downward into a. recess 61 in the disk 20', thence into a perforation 62 opening from the depression 61 to the outer face of the disk 20.

The outer end of the latch (50 is adapted to he moved in and out of engagement with teeth or depressions 3 formed on the inner Face of the disk 29, adjacent to its periphcral edge and in alinemcnt with the perforation 62. The interstices between the tooth 6d correspond in number to the graduations 57 and 58 on the peripheral edges of the disks 20 and 20 and the disk 29.

llcvolubly mounted in the casing 31 to which the indicator bar 11 is attached is a cylinder or drum 64, the outer circumferential face of which is lined longitudinally and peripherally; the peripheral divisions 65 on the drum 64 corresponding in number to the numoer of notations 67 on plate 11. The longitudinal divisions 65 on drum 64 correspond in number (i. e. twenty-four) to the number of chambers 4, and are visible through and are of a width equal'to a slot (.0 which is formed in the face of the casing- I. These longitudinal divisions 65 on drum 04 show the annual interesfiamounts progressively from right to left for 10.20,- etc., up to $1.00, $1.00-to $1000, $10.00 to $100.00, 100.00 "to 1,000,0 $1,000.00 to $10,000.00. Hence, each annual row of peripheral divisions 65 on drum 64 indicates the total interest for one year for any given rate for a given decimal sum.

Formed on the upper face of the plate 11 is a series of transverse divisions 67 which correspond in number to the transverse divisions on the charts 7, (Fig. 8.) which'divisions may be of any desired number: The divisions 67 on the plate 11 and the trans-' verse divisions on the charts, are numbered to indicate various s ums,starting with at the extreme right, as shown in F1 s. 1

. plate 11; the top row of divisions 7' indiand 2, and progressing at the rate 0 10 for each division up to a dollar; thence progressing at the rate of $1 up to $10; thence at the rate of $10 up to $100; from $100 to $1,000, at $100 to each division, and. then from $1,000 to $10,000 at intervals of $1,000; all as inthe case of the divisions '65 on drum 64, Fi 9. The number of thesedivisions may ,increased or diminished, as

occasion may require, and the amounts may be varied as occasion'may require; the ar-' rangeme-nt herein shown and described beingfound as sufii'cient for all practical purposes.

The divisions on the charts 7, are num' bered transversely at 7' in consecutive arra ment from right to left according to the interest on the specific amounts indicated by the divisions -67 on the reading line of eating from right to left the rate of interest for one day on the respective amounts 10, 20, etc, and so on throughoutthe length of the charts 7. The number of transverse rows of divisions 7 on a chart 7 correspond in number to the divisions 57 on the count disk'20, or 365, and are of corresponding widths; each row of divisions 7 being numbered consecutively from 1 to 365, to correspend with said divisions or graduations 57.

The drum 04 is provided with a small sprocket wheel on one end thereof, exterior to the casing 31 a sprocket chain 71 passes around the sprocket 70 and also around the larger spr cket 72 carried by the toothed Wl'Ktl :32. The sprockets 70 and 72 are so pitch d in relation to ea h ther and to the w) 1 in 8 is rotatcd :-l '11 that lid tween adjacent .0 will be cause-'3 to rrvelv" a i to one row pf the longitudinal divisnons'iif) thereon;

the divisions 65 carrying the total annual by the graduations 55; the variousgraduatcd scales and charts all being so related to oppositeany one of the graduations 55 on segment. 35, a corresponding chart 7 computed for that particular interest rate will be positioned adjacent the indicator plate 11 to be engaged by the finger 26, and the drum 01 will be so positioned that a row of divisions (35 thereoncarrying annual interest amounts corresponding to the amounts indicated at the divisions 67 on the reading plate 11 and reckoned at the rate of the particular interest chart will be disposed opposite the slot 31.

in the operation of the invention when it is desired to ascertain interest on a sum, say for instance $10,000, for a period of a' year and eight days at 5%, the drum 3 is rotated by means of the handheld 41 through the .medium of the gear connection previously -4lescribed, to such' a point as to position the indicator 56 in alinement with the graduations 55 on segment 35, representing 5%. 'Releasii'ig the handheld 41 the pawl 45 moves into engagtu'nent with the racks 36 and 37 thereby shifting rack 37 to cause the tin er 40 to engage the arm 27 on shaft 24 an move the hooked linger 26 into engagement with the bar 10 .on a disappearing chart 7 carrying the 5% gradnations. reason of the interlocking of pawl -15 with racks 3(i---37 the drum 3 remains stationary, while the di" 20-20 .are manipulated. The disks l0- 20 are then rotated a sufiicicnt distance to cause the'JSfi-b chart 7 to unwind from its reel until the transverse row of divisions T thereon, numbered 8 to represent 8 days, is exposed at the top edge of the reading plate 11; the division '1" oppositc the division 7 numbered 10,000 will indicate the interest on the sum of $10,000, at the rate of 59"}, for 8 days. The operator then reads the division (i5'von thedrum 64, exposed through the slot 60, for the amount. opposite $10,000 on plate 11. This division will indicate the interest on that sum for a period of 1 year. heated lay the two readings are then added :nnple for a period of time of 1 year and 8 days, In like manner any other example may be worked out for any sum indicated singly or collectively by the-divisions 67 for any length of time from 1 day to any number of days in a year, and for any number of years the number of years being multiples of the. interest rates indicated in the divisions 05 in amounts to be computed intermedi ate the amounts designated on the divisions 07 are obtained by adding the amounts necessary to obtain'the desired result, for ineach other that when the indicator 5 6 is The amounts together, giving the total sum of the eX-' interest corresponding to the rates indicated stance $5550 would require the adding of the indications on the chart 7 at the 5000, the 500 and the designated graduations 67.

It can be seen that various sums can be calculated at any desired rate of interest, as the rates are governed by the charts, and it is only necessary to insert a chart in the drum 3 carrying the interest rates on the .arious amounts enumerated at the desiredrate.

Vhen it is necessary to compute interest from a certain date in one month to a date in some succeeding month, say from July 1st to October 20th, disk 29 is set with the initial date July I opposite the 365th graduation on the companion disk 20, and the disks 20 and 29 are connected together by means of the latch 60. The disks 2020' and 29 are then rotated to dispose the subsee lent date October 20th'on disk 20 on the rca ling line at. the edge of the indicator plate 11; a chart 7 carrying the rates ofthe desired interest, being pieced up by finger 26 and unwound over the surface of the drum 3, as before described. The reading will then be made on the line of a division 7" opposite the date October 20th, indicated by the graduations 58 on the calendar disk 29 in the manner before described.

It is understood that various changes in construction and arrangement may be made without departing from the spirit and prin ciple of the invention.

Having thus described my invention what I claim and desireto secure by Letters Patout is- 1. In an interest calculator, the combination of a rotary drum having a series of longitudinal chambers and slots on its periphery commui'iicating with said chambers,

means for rotating said drums, a series of reels of interchangeable calculating rate charts mountable in said chambers and adapted to be unwound through the slots, and pivoted means turnable in concentric re lation to the drum for engaging the charts singly to unwind same, said pivoted means being actuated by the movement of the drum rotating means.

2. In an interest calculator, the combination of a rotary drum having a series of longitudinal chambers and slots on its periphery communicating with said chambers, a series of reels ofinterchangeable calculating rate charts mountable in said chambers and adapted to be unwound through the slots, means movable around thesurt'ace of the drum for engaging the charts singly to unwind the same over the surface of the drum, stationary means for indicating on the chart the interest of a predetermined amount, and means cooperating with the drum and chart engaging means-for dcter= mining periods of time.

3. In an interest calculator, a rotary drum, means for holding a series of reels of interest calculating charts in said drum, means for rotating the drum to position the charts in reading relation to a reading line, and means for locking the drum against rotat on, said means comprising rack bars and a owl cooperating therewith.

In an interest calculator, a rotary drum, means for holding a series of reels of interest calculating charter in said drum,

means for rotating the drum to position the charts in reading relation to a reading line, means for locking the crum against rotation, and means controlled by the locking of the drum for automatically engaging the calculating charts.

' 5. In. an interest calculator, a rotary drum, means for holdinga series of reels of interest calculating charts in said drum, means for rotating the drum to position the charts in reading relation to a reading line, means for locking the drum against rotation, moans controlled by the locking. of the drum for automatically engaging the calculating charts, and means for moving the chart engaging means around the drum independent thereof.

6. In a calculating machine, the combination of a movable carrier, a disappearing chart thereon, and mechanism which is movable to predetermined distances indicating lapsed time for withdrawing the chart over the surface of the carrier a determinate distance to expose a calculation reckoned for said period of lapsed time. v

7. In a calculating machine, the combination of a movable carrier, an automatically disappearing chart thereon, and mechanism bearing indiciawhich is movable to predetermined distances for withdrawing the chart around the surface of the carrier a determinate distance to expose a calculation reckoned for said indicien 8. In a calculating machine, the combination of a slotted drum, a spring roller carried b 1 the drum, a chart wound on the roller an operative throu h the slot in the drum, means to withdraw he chart and expose it on the surface of the drum, and an indicator bar with means 'for positioning the drum with its slot adjacent to said indicator bar, said positioning means controlling the position of the chart withdrawing means.

9. In-a calculating machine, the combination of a slotted drum, a series of disappearing charts carried thereby, each corresponding to different calculated interest amounts, and automatically controlled means movable over thesurtace of the drum for withdrawing any one of said disappear iao nation of a slotted drum, a series of disappearing eharts carried thereby, each corresponding to different calculated interest amounts, means movable over the surface of the drum for withdrawing any one of said disappearing charts and exposing it over the surface of the drum, and disks connected with said last named means to indicate the desired amount of withdrawal of any particular chart.

ll. In a calculating machine, the com bination of a rotary chart carrier, a series of disappearing charts mounted thereon, each calculated for different rates of interest, a stationary indicator bar, means for positioning the chart carrier with any desired chart arranged adjacent to the indicator bar, meax. for withdrawing a chart so positioned, said lastnamed means comprising a carrier bar operative over the support, and means connected with said carrier bar and cooperating with the indicator bar to determine lapsed time. s.

12. In a calculating machine, the com bination of a rotary chart carrier, a series of disappearing charts mounted thereon, each calculated for different rates ',of interest, a stationary indicator bar, means for positioning the chart carrier with any desired chart arranged adjacentto the indicator bar, means for withdrawing a chart so positioned, said last-named means comprising a carrier bar operative over the support, means connected with said carrier bar and cooperating with the indicator bar to determine lapsed time, said indicator bar graduated progressively from one end to the other for predetermined amounts of principal, and said indicator bar carrying a chart which is progressively figured to represent the annual interest for said respective principal amounts,- and means for operating said last named interest chart synchronously and continuously with the rotary carrier and the particular disappearing chart which is to be withdrawn.

13. In a calculating machine, the combination of a slotted drum,-a disappearing chart carried thereby, a stationary indicator bar graduated corresponding to amounts on which interest may be figured, means for setting the drum with said disappearing chart in juxtaposition with said lndicator bar, a carrier bar operative over the surface of the drum to withdraw said chart therefrom and expose it over the surface of the drum, and a rotary disk carrying said withdrawing means, said disk graduated' progressively from 1 to 365 to designate the amount of withdrawal'of said chart.

14. In a calculating machine. the combination of a slotted drum, a disappearing chart carried thereby, a stationary indicator bar giaduated' corresponding to amounts on which interest may be figured, means for setting the drum with said disappearing chart in juxtaposition with said indicator bar, a carrier bar operative over the surface of the drum to withdraw said chart therefrom, a rotary disk carrying said withdrawing means, said disk graduated progressively from 1 to 365, and a second disk in juxtaposition with said last-named disk circumferentially notched to indicate the months of the year and the days for each month, with means for locking the two disks together to determine the amount of withdrawal of the chart.

15. In a calculating machine, the combination of a rotary carrier, a disappearing calculating chart carried ther eby, independentl y rotatable means for exposing the chart over the surface of the carrier, and rotary calculating disks connected with the carrier for calculating lapsed time.

16. In a calculating machine, the combination of a rotary slotted carrier, a calculating chart housed in a slot in said carrier, with means whereby the chart is normally retained within the periphery of the carrier, an indicator plate, means for positioning the carrier with the chart in juxtaposition to the indicator plate, and means for withdrawing the chart through said slot to expose it to view, said means being controlled by the carrier positioning means.

17. In a calculating machine, the combination of a rotary slotted carrier, a calculating chart housed in a slot in said carrier, with means whereby the chart is 'normally retained within the periphery of the carrier, an indicator plate, means for positioning the carrier with the chart in juxtaposition to the indicator plate, means for withdrawing the chart through said slot to expose it to view, and means connected to said withdrawal means for designating the amount of withdrawal of the chart corre sponding to a predetermined period of time.

18. Ina calculating machine, the combination of a rotary slotted carrier, a calculating chart housed in a slot in said carrier. with means whereby the chart is normally retained within the periphery of the carrier, an indicator plate, means positioning the carrier with the chart in juxtaposition to the indicator plate, means for withdrawing the chart through said slot to expose it to view, and time calculating means movable with the chart withdrawal ineans and readable in conjunction with the chart and said indicator plate.

19; In a calculating machine, the combination of a rotary slotted carrier, a calculating chart housed in a slot in said carcarrier, an indicator plate, means for positioning the carrier with the chart in juxtaposition to the indicator plate, means for withdrawing the chart through said slot to expose it to view, and time calculating means movable with the chart withdrawal means and readable in conjunction with the chart and said indicator plate, said calculating means including a peripherally graduated disk.

20. In a calculating machine, the combination of a rotary carrier, :1 disappearing chart thereon, an indicator plate, means for positioning the chart carrier with the chart in juxtaposition to said indicator plate, means acting independently of the carrier to expose the chart to View, said exposing means being placed into operative position by the carrier positioning means, and time calculating means connected with said chart exposing means for denoting the extent of exposure of said chart.

21. In a calculating machine, the combination of a rotar carrier, a disappearing chart thereon, an indicator plate, means for positioning the chart carrier with the chart in juxtaposition to said indicator plate, means actin independent of the carrier to expose the cunt to view, and time calculating means connected with said chart exposing means, said time calculating means including a graduated movable disk to which said chart exposing means is connected.

22. In a calculating machine, the combination of a rotar carrier, a disappearing chart thereon, an indicator plate, means for ositioning the chart carrier with the chart in juxtaposition to said indicator plate, means acting independently of the carrier to expose the chart to view, and time calculating means connected with said chart exosin means, said time calculating means inclu ing a graduated. movable disk to which said chart exposing means is connected, and a calendar disk graduated to months and days thereof movable with rela tion to the first-named disk and connectihle thereto to rotate said disk and Withdraw the chart.

23. In a calculating machine, the combination of a rotary carrier carrying a plu rality of disappearing charts, each chart calculated to a difierent rate of interest, an indicator plate, means for positioning the carrier with any desired chart in juxtaposition to the indicator plate and means con trolled by said last mentioned means for engaging any chart so positioned.

24. In a calculating machine, the combination of a rotary carrier carrying a pinrality of disappearing charts, each chart calculated to a diflerent rateof interest, an indicator plate, a segment graduated to rates of interest corresponding to the several charts on the carrier, means operating over said segments for rotat' the carrier with means whereby the position of said carrier operating means opposite a particular gradnation on the segment will act to position a chart of the same interest amount in juxiv 'with means whereby the position of said carrier operating means opposite a'particular graduation on the segment will act to position a chart or the same interest amount in juxtaposition to the indicator piste,

means for exposing a disappearing chart is view and time calculating means connected with the chart withdrawmg means and readable in connection with said indicator plate,

28. In a calculating machine, the comhination of a rotary carrier carrying a piurality or disappearing charts,- each chart calculated to a diiferent rate of interest, an indicator plate, a segment graduated to rates of interest corresponding to the several charts on the carrier, means operating over said segment for rotating the carrier with means whereby the position of said carrier operating means opposite a particular grad nation on the segment will act to position a chart of the interest amount in jinn taposition to the indicator piste, means for exposing a disappearing chart to view, time calculating means carrying the chart withdrawing means, time caicniating means including a graduated disk, and a supple mental graduated disk connectihle to and disronncctihle from the first-named graduated disk fr-'1' determining the amount oi": withdrawal of the chart,

2?. in calcuiating machine, the combination of a rotary slotted carrier, a series of interest calculatingrharts carried by the carrier and each operative through a slot in the carrier, each chart calcuiated to different rate of interest, an indicator plate, a roller mounted adjacent to the indicator plate and carrying interest calculations cor espcnding' to interest calculations based on st represented i roiier e2:-

the more no spout the sev 28. In a calculating machine, the combination of a rotary slotted carrier, a series of interest calculating charts carried by the carrier and each operative through a slot in the carrier, each chart calculated to a different rate of interest. an indicator plate, a roller mounted adjacent to the indicator plate 22nd carrying interest calculations corresponding to interest calculations based on the interest rates represented by the several charts, means by which said roller exposes each set of interest calculations separately,

' means by which on the positioning of a particular interest chart opposite the indicator plate the interest calculations corresponding to the rate of interest represented by said chart appears to view on said gradu ated roller, and means for withdrawing the chart so positioned, said withdrawing means being automatically placed into operative position when the particular chart is positioned.

29. In a calculating machine, the combination of a rotary slotted carrier, a series of interest calculating charts carried by the carrier and each operative through a slot 'in the carrier, each chart calculated to a different rate of interest, an indiator plate, a roller mounted adjacent to the indicator plate and carrying interest calculations corresponding to interest calculations based on the interest rates represented by the several charts, means by which said roller exposes each set of interest calculations separately, means by which on the positioning of a particular interest chart opposite the indicator plate the interest calculations corresponding to the rate of interest represented by said chart appears to view on said graduated roller, means for withdrawing the chart so positioned, and graduated disks carrying said withdrawing means for de tor-mining the amount of withdrawal of the chart.-

,30. In a calculating machine, the combinatqm of a rotary slotted carrier, a series of interest calculating charts carried by the carrier and each operative through a slot in the carrier, each chart calculated to a diilerentrateof interest,anindicatorplate, a roller mounted adjacent to the indicator plate and carrying interest calculations corresponding to interest calculations based on the interest rates represented by the several charts, means by which said roller exposes each set of interest calculations separately, means by j which on the positioning of a particular interest chart opposite the indicator plate the interest calculations corresponding to the rate of interest represented by said chart appears to view on said graduated roller, a graduated disk having a movement independent of the carrier, and said disk carrying a bar provided with means for engaging a chart and exposing it to. view,

31. In a calculating machine, the combination of a rotary slotted carrier, a series of interest calculating charts carried by the charts, means by which said rollei exposes each set of interest calculations separately, means by which on the positioning of a particular'interest chart opposite the indicator plate the interest calculations corresponding to the rate of interest represented by said chart appears to view on said graduated roller, a graduated disk having a movement independent of the carrier, and said disk carrying a bar provided with means for engaging a chart and exposing it to view, said graduated disk carrying peripheral graduations which are readable in conjunction with the indicator plate.

32. In a calculating machine, the combination of a rotary slotted carrier, a series of interest calculating charts carried by the carrier and each operative through a slot in the carrier, each chart calculated to a difi'erent rate of interest, an indicator plate, a roller mounted adjacent to the indicator plate and carrying interest calculations corresponding to interest calculations based on the interest rates represented by the several charts, means by which said roller exposes each set of interest calculations separately, means by which on the positioning of a particular interest chart opposite the indicator plate the interest calculations corresponding to the rate of interest represented by said chart appears to view on said graduated roller, a graduated disk having a movement independent of the carrier, said disk carrying a bar provided with means for engaging a chart and exposing it to view, said graduated disk carrying peripheral graduations which are readable in conjunction with-the indicator plate, and a supplemental graduated calendar disk connectible with and disconnectible from said first-named disk for indicating periods of timeand the desired extent of Withdrawal of said charts.

In a calculating machine, the combic nation of a drum having a series of longi-- from the slot of said particular chart to indicate the number of days on \x'hirh interest is to he calculated 34. In a calculating machine, the uninhination of a drinn having a LI'iQS 01' longi tudinally extending peripheral slots and earrying a corresponding series of spring rollers, each roller having an interest chart operative through a respective. slot in the drum, said charts each graduated to expose on successive lines the interest rates for different amounts for si'iecessive days, means for unwinding any ehart to expose it en the surface of the drum, means carrying a bar provided with Sititl' n-ithdrawal means and readable from the slot of said particular chart to indicate the number of days on which interest is to be eaieulated, and a snp plemental graduated calendar diek gruduated to month.- and to days of the month, (sonneetihle with and discennectible from said day calculating means for (ralei'dating; time between tire sucres e dates.

In in calculating machine, the -combi-. nation with a rotary carrier and a plurality of charts rarried th reby, 01' pivoted means for \ritln'rrawing said charts, mean for r tating said rarrier, rack bars for locking said carrier against movement, and a finger .rahiy oi" eharte, (it pivoted means for Withdra 'ing said charts, means for retailing said carrier, rack burs 'lnr .i(,(.'l(l11g said i.\l'11i againstmovement. and a fingercarri xiii one ut the rack bars for rocking the chnrg withdrawing means into operative position.

37. in a calculating machine, the combinatir-n with a rotary Carrier and a plurality of charts carried thereby, of pivoted means for withdrawing said chartfi, means for :0- tating the carrier, :1 fixed rack bar and a Sliding rack bar at one end of the carrier, a pawl engaging said raeks to lock the carrier against relation. and a crank carried by the. sliding: rarlc, said rrnnk I'Otflii'lg the chart \\'itii('il'2l..'lll 1' means into operative pnsitic'n. in te:-iiimnny whereut I have hereunto set my hand in the 'presenre 0t tam snlieerihing witnesses.

JOE iN M. AIACLEAN.

\Vitnesses M. l). Nonvnen, Ronenns. 

